Swift TranslatesAutoResizengMaskintroConstraints无法分配

当我写代码时：swift代码

我写它是为了解决一个布局问题，我的标签一直停留在左角

label.translatesAutoresizingMaskIntoConstraints = false

我得到这个错误：

"Cannot assign to the result of this expression"

我的函数Nextlevel是我无法分配自动调整大小语句的标签：

@IBAction func check(sender: AnyObject) {


    var strValue = boxShots.text
    var floatValue = Double((strValue as NSString).integerValue)
    var strValue2 = boxMakes.text
    var floatValue2 = Double((strValue2 as NSString).integerValue)
    var stage = "stage 2"
    var procent = floatValue2 / floatValue * 100
    if floatValue < 99
    {
        stageText.text = "text text";
    }

    else if floatValue > 99 && floatValue2 > 49 && procent > 49.99
    {

        stageText.text = "test text"

    } else {
        stageText.text = "test text"

    }
    if floatValue > 99 && floatValue2 > 49 && procent > 49.99
    {
        nextLevel.translatesAutoresizingMaskIntoConstraints = false
        nextLevel.center = CGPointMake(160, 284)
        nextLevel.textAlignment = NSTextAlignment.Center
        nextLevel.userInteractionEnabled = true
        nextLevel.text = "Go to next stage"
        self.view.addSubview(nextLevel)

        let gestureRecognizer = UITapGestureRecognizer(target: self, action: "handleTap:")
        nextLevel.addGestureRecognizer(gestureRecognizer)

    }

func handleTap(gestureRecognizer: UIGestureRecognizer) {
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let vc: AnyObject! = storyboard.instantiateViewControllerWithIdentifier("stagethree")
    self.presentViewController(vc as UIViewController, animated: true, completion: nil)
}


}

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显示更多codelabel.TranslatesAutoResizezingMaskinToConstraints=false label.center=CGPointMake160，284 label.textAlignment=NSTextAlignment.Center label.userInteractionEnabled=true label.text=转到下一阶段self.view.addSubviewlabell让GestureRecognitizer=UITapGestureRecognitizer目标：self，操作：handleTap:label.addgestureRecognitizergestureRecognitizer不确定如何在更漂亮的垂直视图中显示我的代码？对不起@把它添加到问题中，而不是在注释中-在文本成为代码块之前，还需要显示label4空格的定义